That's true, but that's always been true. Historically as well as today, when you buy / sell / trade Bitcoin on exchanges, until you move those coins to self custody, no UTXO is created.

As you say, when MSTR or TSLA buy Bitcoin, Coinbase just change an entry in their internal ledger.

Ordinals have been responsible for the deluge of transactions for over a year now, they are still in the queue, but few new ones are showing up.

What's happening?